Support is requested for continued development and expansion of the National Archive of Computerized Data on Aging (NACDA). The broad goal of the project is to encourage and facilitate empirical research on aging. The project will accomplish this goal by acquiring and processing collections of computer-readable research data, providing researchers with multiple modes of access to these data including provision of data in technical forms suited to diverse computing environments, informing researchers of the availability of these data and of their research potentialities, and by providing assistance in the use of the data. The NACDA project employs the archival, informational and data distribution facilities and expertise and the institutional membership network of the Inter-university Consortium for Political and Social Research (ICPSR). The project builds upon two prior two-year center grants from the National Institute on Aging and earlier joint support by NIA and the Administration on Aging.